Elizabethkingia meningoseptica, formerly known as Chryseobacterium meningosepticum, is a non-motile, non-fastidious, catalase and oxidase-positive, aerobic, glucose-non-fermentative Gram-negative bacillus first defined by Elizabeth O. King in 1959. Formerly the most pathological member of the Chryseobacterium genus, it was reclassified into the genus Elizabethkingia in 2005. [1] Elizabethkingia genus has been noted for its genes that grant it great degree of genetic variability and subsequent antimicrobial resistance. This fact combined with lack of literature, wide distribution in nature, and lack proper treatment regimens have led to high mortality rates in hospital-settings, particularly in Intensive Care Units since 2004. [2] This has led to increased interest in E. meningoseptica as an emerging pathogen in the past decade.
E. meningoseptica are most frequently isolated from soil, saltwater and freshwater and from dry and moist clinical environmental and equipment surfaces, intravenous lipid solutions, and municipal water supplies including those which have been adequately chlorinated. [3] Although nearly ubiquitous in nature, it is an uncommon human pathogen. E. meningoseptica predominately causes outbreaks of meningitis in immunocompromised patients, particularly in premature newborns and infants in neonatal intensive care units of developing countries. [4] The bacterium is a rare cause of nosocomial pneumonia, endocarditis, and meningitis in immunocompromised adults. Recently in the past few years, it has been found to cause soft tissue infection and sepsis in immunocompetent adults. [5]
In a study from Wisconsin, 48 cases of Elizabethkingia were reported during an outbreak, which resulted in 17 deaths in a 5-month period beginning in November 2015. [9] Most data on E. meningoseptica related septicemia is derived from Taiwan. A large case series showed that yearly incidence of E. meningoseptica bacteraemia increased substantially from 2002 (from 6.8–13.1 to 26.6–39.9 per 100,000 admissions; P = 0.006). [10] A recent review of literature suggests that almost all cases of septicemia from E. meningoseptica occur in a nosocomial setting. [3]
Moreover, Elizabethkingia, alongside its genetic relative chryseobacterium spp., are inherently extensively drug resistant. They are resistant to broad spectrum of antibiotic classes, including marcolides, tetracyclines, linezolid, polymyxin group, chloramphenicol, aminoglycosides, and beta-lactam drugs. [11] Vancomycin, rifampicin, new fluoroquinolones, piperacillin-tazobactam, and minocycline the current preferred empirical choices for E. meningoseptica infections. [3] Tigecycline as the preferred drug of choice for infections is currently being studied. [3]
Elizabethkingia meningoseptica is an important emerging opportunistic bacterium that primarily occurs in nosocomial settings. Given its ubiquitous nature, arsenal of multidrug resistant genes, and affinity to infect primarily the immunocompromised; it is paramount that more resources be devoted to study this emerging pathogen. It is also unclear as to which treatment regimen is most effective and what are the factors associated with adverse outcomes. The aim of this study is to describe the clinical features and outcomes of Elizabethkingia meningoseptica infections in a tertiary care center at Karachi, Pakistan. Furthermore, a systematic review of literature regarding this pathogen is also presented in this study.